Convert Decimals to Percents
"Percent" means "per 100" so:Multiply the Decimal Number by 100, and put the "%" sign so people know it is per 100.
Example: Convert 0.125 to percent
Multiply 0.125 by 100:
0.125 × 100 = 12.5
Put the percent sign:
0.125 × 100 = 12.5%
Answer 0.125 = 12.5%
The easy way to multiply by 100 is to move the decimal point 2 places to the right. so:
From Decimal  To Percent  
move the decimal point 2 places to the right (and add the "%" sign!) 
More Examples:
Example: Convert 0.35 to percent
Move the decimal point two places to the right: 0.35 → 3.5 → 35.
Add a % sign: 35%
Answer 0.35 = 35%
Example: Convert 0.985 to percent
Move the decimal point two places to the right: 0.985 → 9.85 → 98.5
Answer 0.985 = 98.5%
You may also need to add zeros on the right to move the decimal point:
Example: Convert 1.2 to percent
Move the decimal point two places to the right: 1.2 → 12. → 120.
Answer 1.2 = 120%
Why
These all mean the same thing:

So 0.5 (a decimal number) = 50% (a percentage)
The "%" tells you that there is a hidden "/100" there.
Another example:

So 0.25 (a decimal number) = 25% (a percentage)